Welcome to the home of DoISO, the free ISO maker (and now CD/DVD Burner!) for Windows.
DoISO is a simple GPL'd, free ISO creation frontend for mkisofs, the ultimate ISO creating utility. One day I wanted to make a DVD-sized ISO but found that my previously trusty ISO utilities would only go to CD size. mkisofs was the only utility available, and it required reading the manual every time I wanted to make a quick ISO, so in Reality there was no such thing as making a quick ISO :(. I decided enough was enough, I had to have a reliable GUI for making any size ISO that I wanted, so I went back to some old commandline wrapping code I had used in another project (Mike Mayer's process launch code) and simply wrapped mkisofs.